The first thing you need to know when using an herbicide such as Drive XLR8 Herbicide is that the exact amount of water you dilute it with is not important. It is only important to make sure you are using the correct amount of product per 1,000 sq ft of lawn. Use too much and you risk damaging your lawn, use too little and you will not get adequate results. You will need to use 1.45 oz per 1,000 sq ft . To decide how much water you want to use, you should mark a 1,000 sq ft area, fill your sprayer with water ONLY, and start walking and spraying just as if you were doing the actual application of herbicide. When you are done walking and spraying the 1,000 sq ft area note how much water it took you to spray that area, and that is the amount you will want to mix 1.45 oz of product with for each 1,000 sq ft area that needs to be treated. You will need to make sure treated areas are irrigated with at least 1/2 inch of water (either by rainfall or by sprinkler) following the application.
We have an entire page on our site that contains crabgrass killing products that are selective, meaning they will kill crabgrass and other weeds, but not harm your grass. Here is a link to the section: http://www.domyownpestcontrol.com/post-emergents-c-188_478_494.html
The first product on the page, Drive XLR8, is our most popular.
The first thing you need to know when using an herbicide such as Drive XLR8 Herbicide is that the exact amount of water you dilute it with is not important. It is only important to make sure you are using the correct amount of product per 1,000 sq ft of lawn. Use too much and you risk damaging your lawn, use too little and you will not get adequate results. You will need to use 0.50 - 1.45 oz per 1,000 sq ft (please read the product label for the exact usage rate needed for your application) . To decide how much water you want to use, you should mark a 1,000 sq ft area, fill your sprayer with water ONLY, and start walking and spraying just as if you were doing the actual application of herbicide. When you are done walking and spraying the 1,000 sq ft area note how much water it took you to spray that area, and that is the amount you will want to mix 0.50 - 1.45 oz of product with for each 1,000 sq ft area that needs to be treated. You will need to make sure treated areas are irrigated with at least 1/2 inch of water (either by rainfall or by sprinkler) following the application. Please contact your local cooperative extension office to determine the correct timing of the application as this will vary greatly from region to region.
Unfortunately their is not a selective product that will remove crabgrass from St. Augustine. St. Augustine is a very fragile grass, and so most selective products that are labeled to remove crabgrass and not your real grass, will hurt the St. Augustine. It is recommended to kill the crabgrass with a round up type product, like Ranger Pro, which will also kill just the St. Augustine around the crabgrass that it is sprayed on, and then a couple weeks later re-seed those areas with new St. Augustine.
For long term control though, you should apply a pre-emergent in the late fall and early spring which will prevent new crabgrass from coming up next year. If you apply pre-emergent every year, you should not have issues with crabgrass long term. Dimension 2EW is one of our most popular pre-emergents for crabgrass.